Crohn's disease.

that time. Because of this reflex we doubt the efficacy of screening boys for undescended testes at 1 year and at school entry. The figures from Tamhne et al confirm our opinion that too many boys will be operated on unnecessarily because of retractility of the testes. In 1989 a retrospective cohort study concerning the localisation of the testes from birth until puberty of 853 boys born in 1973 and living in West Friesland (The Netherlands) was done. In this study, which has been submitted for publication, we found a considerable number of boys with one or two undescended testes, that when previously measured, had been registered as scrotal. In all these boys the testes had assumed a normal scrotal position at puberty. This supports our advice that if the testes were descended no further screenings are necessary. We agree with Tamhne et al that there is a need to set clear guidelines for the diagnosis of undescended testes and for referral pathways. This is important especially to prevent unnecessary operations.